Communication systems are known. A communication system enables communication between two or more entities such as user equipment and/or nodes implemented in the system. Communication systems typically operate in accordance with a given standard or specification which sets out what the various elements of the system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment or terminal is provided with a circuit switched service and/or a packet switched service. Communication protocols and/or parameters which shall be used for the connection may also be defined. In other words, a specific set of “rules” on which the communication can be based on needs to be defined to enable communication in the system.
Communication systems proving wireless communication for the user terminals or other nodes are also known. An example of the wireless systems is a cellular network. In cellular systems, a base transceiver station (BTS) or similar serves mobile stations (NS) or similar wireless user equipment (UE) via an air or radio interface between these entities. A base station provides a radio access entity that is typically but not exclusively referred to as a cell. The operation of the base station apparatus and other apparatus required for the communication can be controlled by one or several control entities. The various control entities may be interconnected. One or more gateway nodes may also be provided for connecting the cellular network to another networks, e.g. to a public switched telephone network (PSTN) and other communication networks such as an IP (Internet Protocol) and/or other packet switched networks.
A cellular communication system may be adapted to provide packet switched (PS) services for a mobile station. Examples of systems enabling packet switched services include the General Packet Radio Service (GPRS), the Enhanced Data rate for GSM Evolution (EDGE) mobile data network, the third generation (3G) telecommunication systems such as the Universal Mobile Telecommunication System (UMTS), i-phone or IMT-2000 (International Mobile Telecommunications) and the TErrestrial Trunked Radio (TETRA) system.
For example, in the current third generation (3G) architectures it is assumed that several different servers are used for handling functions required by various stages of processing of communication between two entities. These functions include different call state control functions (CSCFs) such as a proxy call stare control function (P-CSCF), interrogating call state control function (I-CSCF), and serving call state control function (S-CSCF). Control functions may also be provided by entities such as a home subscriber server (HSS) and various application servers. From the above mentioned servers the home subscriber server HSS is for storing subscriber relates information such as the registration identities (ID) of the subscriber or the terminals and so on. The home subscriber server HSS can be queried by other function entities during call or other session set-up procedures, e.g. for locating a subscriber. The term “session” refers to any communication such as to a call communication, data communication (e.g. web browsing) an so on.
However, the home subscriber server does not store dynamically any call related information or other information that relates to the status of a subscriber. In particular, the current network system are not provided with means for storing dynamically call related information or other information that relates to the status of a subscriber. For example, the home subscriber server HSS does not provide indication whether a subscriber is busy. Furthermore, e.g. in the packet switched environment a subscriber may have simultaneously one or more multimedia connections that are handled by different and from each other independent servers. The home subscriber server does not know if the subscriber is already having one or more of multimedia connections.
However, various network entities and/or services or other users may require information regarding the status of a certain subscriber or a call for their operation. An example of such a service/entity is the so called presence service/presence server.
In addition to “internal” clients, i.e. entities that are located within the network, the status information could be found useful by external clients. A client could be, for example, an user of a terminal or an entity that belongs to another network. For example, a user may want to know the status (e.g. availability) of another user (B-party). The user may find this information useful e.g. before trying to make a call to the B-party.
At present, for example in the GSM, the status of the B-party is checked over air interface. That is, a message is transmitted over the air interface to the B-subscriber mobile station. If the B-party mobile station receives the message it subsequently signals a response regarding the status thereof back to the network over the air interface.
A single network entity (e.g. the serving call state control function) may provide overall control for a connection. That is, the connection control can be “anchored” to and be provided by a serving network entity. This serving entity could be used to provide information that associates with a connection controlled by said entity. However, the inventors have found that this is not possible in the present network designs where the control functions of the multimedia or any other services may be distributed to be handled by different entities.
The inventors believe that services such as the presence service will become more popular among the users. Thus it must be assumed that the new services are generating a lot of new traffic into core network. The amount of traffic over the air interface generated by the new services may become substantially high and the possibility of overloading the air interface capacity may become a problem especially in the currently proposed 3G systems. Thus the inventors have found that an advantage could be provided if the status inquiry could be arranged to occur such that the inquiry is not transmitted over the air interface to the B-party mobile device as this wastes the limited air interface resources.
Another way of responding these queries could ease the capacity problem. However, the inventors have found that the present network arrangements are not capable of providing the information that is required e.g. by the presence service in such a way that it could readily accessed by an entity requiring the information. The prior art proposes no feasible solution for the storage and dynamic update of the status information and for the provision of this information for clients.